73 research outputs found
Properties of pulsed entangled two-photon fields
The dependence of one- and two-photon characteristics of pulsed entangled
two-photon fields generated in spontaneous parametric down-conversion on the
pump-pulse properties (shape of the pump-pulse spectrum and its internal
structure) is examined. It is shown that entangled two-photon fields with
defined properties can be generated. A general relation between the spectra of
the down-converted fields is established. As a special case interference of two
partially overlapping pulsed two-photon fields is studied. Fourth-order
interference pattern of entangled two-photon fields is investigated in the
polarization analog of the Hong-Ou-Mandel interferometer.Comment: LATEX2e, 8 pages, 9 PostScript figure
Relation between squeezing of vacuum fluctuations, quantum entanglement and sub-shot noise in Raman scattering
A completely quantum description of Raman process is used to investigate the
nonclassical properties of the modes in the stimulated, spontaneous and
partially spontaneous Raman process. Both coherent scattering (where all the
initial modes are coherent) and chaotic scattering (where initial phonon mode
is chaotic and all the other modes are coherent) are studied. Nonclassical
character of Raman process is observed by means of intermodal entanglement,
single mode and intermodal squeezing of vacuum fluctuations, sub-shot noise and
wave variances. Joint photon-phonon number and integrated-intensity
distributions are then used to illustrate the observed nonclassicalities.
Conditional and difference number distributions are also provided to illustrate
the nonclassical character. The mutual relation between the obtained
nonclassicalities and their variations dependent on phases, rescalled time and
ratio of coupling constants are also reported.Comment: 12 pages, 9 figure
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